package com.t14;

import net.mindview.util.Null;

/**
 * Created by xuyiwei on 2018/8/11.
 */
public class Person {
    private final String first;
    private final String last;
    private final String address;
    public Person(String first, String last, String address) {
        this.first = first;
        this.last = last;
        this.address = address;
    }
    public String toString(){
        return "Person:"+first+" "+last+" "+address;
    }
    public static class NullPerson extends Person implements Null{
        public NullPerson() {
            super("None", "None", "None");
        }
        public String toString(){
            return "NullPerson";
        }
    }
}
